21149145 has 24 divisors (see below), whose sum is σ = 36818496. Its totient is φ = 11230368.

The previous prime is 21149131. The next prime is 21149171. The reversal of 21149145 is 54194112.

It is not a de Polignac number, because 21149145 - 2⁴ = 21149129 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10942 + ... + 12728.

It is an arithmetic number, because the mean of its divisors is an integer number (1534104).

Almost surely, 2^21149145 is an apocalyptic number.

It is an amenable number.

21149145 is a deficient number, since it is larger than the sum of its proper divisors (15669351).

21149145 is a wasteful number, since it uses less digits than its factorization.

21149145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2061 (or 2058 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 21149145 is about 4598.8199573369. The cubic root of 21149145 is about 276.5440199277.

The spelling of 21149145 in words is "twenty-one million, one hundred forty-nine thousand, one hundred forty-five".